Draft responsive safety control for oil burners



Oct. 27, 1953 P. s. RUSSEL 2,656,884

DRAFT RESPONSIVE SAFETY CONTROL FOR OIL BURNERS Filed Dec. 15, 1950 2 Sheets-Sheet l I INVENTOR. P&ZZZ/ J Passe].

A TrQ/M K P. S. RUSSEL Oct. 27, 1953 DRAFT RESPONSIVE SAFETY CONTROL FOR OIL BURNERS 2 Sheets-Sheet 2 Filed Dec. 13 1950 INVENTOR )fqsseZ.

Patented Oct. 27, 1953 OFFICE DRAFT RESPONSIVE SAFETY CONTROL FOR OIL BURNERS Philip S. Russel, Detroit, Mich. Application December 13, 1950, Serial No. 200,564

7 Claims.

This invention relates to heating apparatus and has particular reference to a new and improved control means for an oil burner whereby the supply of oil to the burner is automatically shut off upon stopping of the supply of air to the burner or upon failure of the motor or the fan driven thereby to function properly.

The invention is particularly adapted for use in a domestic pot type oil burner, although it is not limited to such use.

A principal object of the invention is to provide a safety control for oil burners.

A further object is to provide an oil burner having an automatically operable control for shutting off the fuel supply upon stopping or failure of the fan for supplying air to the burner.

Another object of the invention is to provide a control device for an oil burner having a motor driven fan for supplying air to the burner, which control includes a means for opening the circuit of the motor upon failure of the fan.

A further object is to provide a control device for oil burners in which a means responsive to the suction of a motor driven fan is operable to shut off the supply of fuel to the burner upon stopping of the fan.

Other and further objects of the invention will be apparent from the following description and claims and may be understood by reference to the accompanying drawings, of which there are two sheets, which by way of illustration show preferred embodiments of the invention and what I now consider to be the best mode in which I have contemplated applying the principles of my invention. Other embodiments of the invention may be used without departing from the scope of the present invention as set forth in the appended claims.

In the drawings:

Fig. 1 is a fragmentary sectional view of an oil burner embodying this invention;

Fig. 2 is an enlarged sectional view taken along lines 2-2 of Fi 1;

i Fig. 3 is a top plan view of a control valve for controlling the supply of fuel to the burner;

Fig. 4 is an elevational view of the motor driven fan;

Fig. 5 is a fragmentary sectional view similar to Fig. 2, showing the control valve in its closed position; and

Fig. 6 is a fragmentary sectional view showing an alternative arrangement of certain parts of the control.

Referring more particularly to the drawings,

in Fig. 1 there is disclosed an oil burning hot air heater which comprises an outer casing I0 having a combustion chamber 12 therein provided with a flue I4 for conducting products of combustion to the atmosphere, which flue is surrounded by a conduit [6 having an enlarged lower end l8 surrounding the combustion chamber and arranged to conduct air to be heated downwardly around the flue l4 and the combustion chamber l2 and into a warm air pit 28 from which the air is supplied to suitable registers through conduits 22 communicating with the warm air chamber 20. Air to be heated may be forced downwardly through the conduit 16 by a suitable fan (not shown).

A burner pct 24 is arranged within the combustion chamber and is supplied with liquid fuel through fuel line 26. Air is supplied to the burner by means of a fan indicated generally at 28 driven by an electric motor 29, which fan discharges air through the conduit 30 into the lower part of the combustion chamber I2. The air then passes upwardly through a central opening in a plate 32 and into the burner through suitable apertures provided in the cylindrical wall thereof.

A storage tank (not shown) for oil or other liquid fuel supplies fuel through the fuel line 34 into a fuel reservoir 36, from which reservoir the oil is discharged into the burner through the line 26. The fuel reservoir 35 includes certain control means for controlling the flow of fuel into the burner and may be similar in construction to the liquid level controlling means shown in my Patent No. 2,317,556, issued April 27, 1943.

The control device comprises in general a casing 38 supplied with liquid fuel from the storage tank through the inlet 40 which is provided with a valve body 42 having a valve seat 44 and outlets 46 from which oil is discharged into the casing 38. A valve member 48 having a conical head is arranged to seat on the valve seat 44 for shutting oil? the supply of fuel from the storage tank to the burner. The casing 38 includes a part 50 on the upper end of which is secured a pin 52 by means of a clamping screw 54. A channel-shaped lever arm 56 is pivotally mounted on the pin 52 which extends through elongated slots 58 provided in the sides of the lever 55. The bottom wall of the lever 56 is provided with an opening through which the valve member 48 extends. The valve 48 is provided with a pin 60 seated against the under side of the lever 56 and biased into engagement with the lever by a leaf spring 62 through which the valve 48 extends.

A supporting arm 64 depends from the lever 56 and a fluid-tight float member 66 is secured to the end of the arm 64. A weight 68 is secured to the other end of the lever 55 so as to partially counterbalance the weight of the float 66. The normal level of oil Within the casing 38 is shown by the dotted line in, and it will be seen that the valve 48 is controlled by means of the float member 66 which is responsive to the level of oil within the reservoir so as to pivot the lever 56 about the pin 52, which pivoting movement of the lever 56 opens or closes the valve 48so as to;controltthe flo'vv 'of oil from. the storage tank into the reservoir: The float valve will maintain the level of oil within the reservoir relatively constant.

The reservoir is provided with: a1suitable:ariajustable metering valve I2 which permits'athei flow of oil at a predetermined rate. from the,

reservoir through the line 26 into theburner M. The particular construction .oiJthe meteringwalVe 12 forms no part of this invention.

A valve actuating member 14 pivoted-- try" a" bracket I6 secured to thecasing 38 is engageable with the va'lve 48 forclosing-er seating the valve member under the conditions hereinafter. set for-th Abracket I8 secured to-the:opposite:wal1.- of the casing is provided with a-horizontally-projecting end- 80' between which end: and:' an: end- Broi -the actuating member I I is-a compression spring 84- normally: tensioned to expand and bias the actuator'T-t' to the-position shown inFi'g. 5.: In this position it Will' beseen that -the'-member 14 engages-the upper end of the valve 481 so. as to seatthe valve on its. val v-e seat' hl so as toshut off the flowoffuel into the reservoir. The ac:- tuating member I4 has a part 86: projecting through a verticallyextending: slot provided. the casing 38. The-projectingend 88 of the part 8'0- provides a handgr-ip for manually resetting-2 the actuating member 141111130 thiepositionshown: in Fig. 2 soas to' -permit the valve fls to be: conetrolled by" the float 6'62 latch mem'ber. 90 152 pivotally mounted on the bracket I8: and. providesa means -for positioning theactuatingmember M sc as-to per-mit the=val ve48 to bemoved toward and away: from its-seat di l by the float 66, as shown in Fig. 22 The-part 861' is provided with a locking member: 92 engageable with a notch 94 provided" on the' latch 90 for holding the actuating member 14 in the position shown: in Fig. 2. Thelat'ch 9'ilhas an errdi96 projecting throughthe vertical. slot providedin the 03S! ing 38.

The lever 55 is' providedwith anv extension 98 arranged-to engage' the end IOEof: the latch: 90 when the lever li i's pivoted'a sufficient'iamounti bythe float B6due to a rise in the: level: of; oil.

in the reservoir above a predetermined: level.

Engagement of the extension 98 with. the: end I00 ofthelatchfill will'release theilocking -meme b'er 92 from the notch 94 in the latch: 00. thereby: releasing the actuating member IA; which. under the influence of the spring 04 will therr close the valve 48';

If during operation: ofthe burner: the: fan 28. should stop for any reason, suchas mechanical: failure or: failure:of5 the motor, it: is desirable to stopthe flow of fuel to the-burner since it is: necessary to provide fueland air tor-theb'urnen in' proper ratioirr. orden to-insure eflicientr com-x bustionand inorder toprevent excessivessoot andcarbon from' forming. in the: burners whenv an: insuflicient amount: of; air iss, delivered; to the burner. To accomplish this. result: Iihave: pro-- vided a -means which: is; responsive: toa thersuction created by the: famandsengageable: withthe: end: 96 ofthe latch". 90' for. releasing the? member: It? to close the valve 48 uponstoppin'g ofsthezfanzor. upon failure ofthe ianltotdeliver'apredetermined; amount of air to the burner: suchimeans comeprises a- -draft responsive plate on damper." I02 pivotallymounted on the tam-casing atthe: inleti thereof. The damper is provided: withia-shaft I04 secured thereto, and which shaft is rotatable within the ends I06 of clips I08 secured to the fan casing. The damper has an arm I I0 formed integrally therewith andiarranged tot engage the end' 'of'tlie' latch 90. When the" fan" is not in operation the damper I02 will be in its open position as shown in Fig. 5, due to the force of gravity- Whenthe: fan is operating, the suction createdby the fan at the inlet thereof is suflicient to hold the damper against the force of gravity in the position shown in Fig. 2. If for any reasonreither; thezfa-n or the motor should cease normal operation, the suction at the inlet of the fan will-no longer be sufilcient to hold the damper in its closed position and the damper will pivot to its open position, thereby engaging-the? latch 90 and closing theva-lve I 48'.- It :willbe noted. that although the: inlet to: the reservoir: isv closed. at such time, the: oil within the reservoir. will be permitted to: flow tothe burner through the. metering valve 12. However,:the.: quantity. of 011' within the reservoir is relatively small and the burner will operate-for: only a very short; time after. closing ofthe valve 4&1 It should also. be; noted that opening otthe damper: I02- permits: air: to: flow: through that part of the. fan. inlet formerly closed by the:damper-so that: such air may be utilized for: supporting. combustion. of the small quantity Of OiliWhiCh willibe discharged from:-the; reservoir after. closing of: the. valve;

Thefan-isialso providedlwithras damper mem'a ber I123 pivoted at one' end to. the: fan casing. by a s'crew.. I li:- and adaptedrto be secured-:inzany. adjusted positionby; means of. a screw: LI 6. The damper I=I2 may" be: suitably adjusted: so as. to permit the: proper amount of: air: to: be delivered: to the burner;

The control device: may also: include azmeans' for stopping the motor 2'9 up0njai1ure or stop;- pingof the 1 fan. A .mercuryr switch- I I 8; may be secured to the arm IIO of thezdamper I02 and hasits contacts:conn'e'cted bywires H9 and HI to a conventional source oi. electric. current. and to'the': motor 29 respectively;,as shown in Fig. 2.. 1 Wire: I23: is also electrically conn'ectedzto motor 2'9:a-nd t'o -the currents source' so that: the:- switch I-tB iS ar-ranged in the' motorLcircuitl Theswitoh I I8': shown in: Fig; 2: iszclosedawheni the; damper:

102 is in: its closed position? during. operation: of. the fan;'- Opening of thedamper I02 will open; the i switch '8: so as-- to open the: circuit. through the match The damper I02 mustbez manually closed so as to close switch. I118: andzthe. motorcircuit, thereby causing operation. of: fan: 28 and establishing a draftto. hold-the. damper: closed.

In Fig. 6 thereisedisclosedranialternativear rangement for: the: switch I 18; IhiihiS modification the switch H8 i mounted cilia-bracket- I20 seoured' t'othe actuating: arm Tiandarranged so as to be opened upon movement .cftthear-m 14-to close:-the valves4B.:

During normal operation of the burner the: aetuatingmember: Maismanually. set in itSElOCkBd position and the:: damper: I 0 22 iSL movedzmanuaIIyI into the fan inlet so as to be maintained therein by the suction created-asbyi the: fan; The control valve 48': at such timer iss operated-byath'e float 66 which is responsive to the level of oilinthe IBSGIF vein. The vvalve: 48 will. be: closedby, the. float membenfifi and lever 5fi1if'.-th8 oil inthe reservoir. reaches;.1aa predeterminedrmax-imum leveland the. valve 48r willlalso be -closed by the. damper I02-in: thelevent of motor. or: fanfailure.

While-J1 have: illustratedland described, pre-. ferrediembodimentswof my; invention, itisunderstood that these are capable of modification and I therefore do not wish to be limited to the precise details set forth but desire to avail myself of such changes and alteration as fall within the purview of the following claims.

I claim:

1. Fuel burning apparatus burner, a gravity feed fuel supply device for supplying fuel to said burner, a motor-driven fan for supplying air to said burner, said fuel supply device including a fuel reservoir from which fuel is supplied to said burner and a float control valve for controlling the flow of fuel to said reservoir in response to the level of fuel in said reservoir, an actuating member engageable with said valve for closing the same, latch means for positioning said actuating member out of engagement with said valve so as to permit said valve to be opened, a draft responsive plate pivotally mounted on said fan at the inlet thereof, said latch means being arranged in the path of movement of said plate, said plate being responsive to the suction created by said fan at said inlet so as to be maintained out of engagement with said comprising a latch means by said suction upon operation of said fan, said plate being arranged to pivot into engagement with said latch means so as to cause the same to release said valve actuating member for closing said valve upon stopping of said fan.

2. Fuel burning apparatus comprising a burner, an electric motor-driven fan for supplying air to said burner, a gravity feed fuel supply device for supplying liquid fuel to said burner including a reservoir provided with an inlet and an outlet, fuel being supplied to said burner from said outlet of said reservoir, a valve for controlling the fiow of fuel to said reservoir through said inlet, an actuating member engageable with said valve for moving the same so as to close said inlet, latch means for positioning said actuating member so as to permit said valve to be opened, a float member connected to said valve for controlling the opening of said valve in response to the level of fuel in said reservoir, a plate pivotally mounted on said fan at the inlet thereof and responsive to the suction created by said fan at said inlet so as to be maintained in one position by said suction during operation of said fan, said latch means having a part thereof arranged in the path of movement of said plate, said plate being arranged to pivot into engagement with said latch means for causing the same to release said actuating member for closing said valve upon stopping of said fan.

3. Fuel burning apparatus according to claim 2 including a switch arranged in the electrical circuit through said motor and arranged to be closed during operation of said fan and to be opened for stopping said motor upon engagement of said plate with said latch means.

4. Fuel burning apparatus comprising a burner, mean for supplying liquid fuel to said burner including a valve for controlling the flow of fuel through said supply means, an electric motor-driven fan for supplying air to said burner, a draft responsive plate movably mounted on said fan at the inlet thereof and responsive to the suction created by said fan at said inlet so as to be maintained in one position thereof by said suction during operation of said fan, said plate being arranged to move into another position thereof upon discontinuance of said suction, mechanical means interrelating said plate and said valve and operable upon movement of said plate into said other position to close said valve, and a switch arranged in the electrical circuit through said motor, said switch being arranged to be opened for stopping said motor when said mechanical means is actuated by said plate.

5. Fuel burning apparatus according to claim 1 wherein said switch comprises a mercury switch secured to said plate.

6. Fuel burning apparatus comprising a burner, means for supplying liquid fuel to said burner, an electric motor-driven fan for supplying air to said burner, a valve for controlling the flow of fuel to said burner, an actuating member engageable with said valve so as to close said valve, a latch member for positioning said actuating member so as to permit said valve to be opened, means engageable with said latch memher so as to release said actuating member for closing said valve comprising a draft responsive plate pivotally mounted on said fan at the inlet thereof and responsive to the suction created by said fan at said inlet so as to be maintained out of engagement with said latch member by said suction during operation of said fan, said plate being arranged to pivot into engagement with said latch member upon discontinuance of said suction, and a mercury switch carried by said actuating member and arranged in the circuit through said motor, said switch being arranged to be closed when said actuating member is positioned by said latch member so as to permit said valve to be opened and arranged to be opened for stopping said motor upon closing of said valve by said actuating member.

7. Fuel burning apparatus comprising a. burner, a motor-driven fan for supplying air to said burner, a gravity feed fuel supply device including a reservoir for supplying liquid. fuel to said burner, said reservoir being positioned adjacent the inlet to said fan, a float control valve in said reservoir for controlling the flow of fuel therethrough in response to the level of fuel in said reservoir, an actuating member engageable with said valve for closing the same, a latch member for positioning said actuating member so as to permit said valve to be opened, a draft responsive plate pivotally mounted on said fan at the inlet thereto and movable toward and away from said inlet, said latch member having a part thereof positioned in the path of movement of said plate, said plate being responsive to the suction created by said fan at said inlet so as to be maintained out of engagement with said latch member by said suction upon operation of said fan, said plate being arran ed to be pivoted by gravity into engagement with said latch member upon discontinuation of said suction, thereby actuating said latch member for releasing said actuating member for engagement with said valve so as to close the same.

PHILIP S. RUSSEL.

References Cited in the file of this patent UNITED STATES PATENTS 

